Virtual machine technologies are known in which a virtual machine is implemented by software on a computer such that an OS is implemented and an application is executed on the virtual machine. If the OS is shut down when the OS and the application are being caused to operate on the virtual machine, it is necessary to dump and store the contents of a memory that is used by the OS in order to investigate the cause of the failure.
In a conventional technology, to retain information, an OS may not be restarted while a dump is being captured. Therefore, operations that are stopped because the OS is shut down may not be restarted until capturing a dump is completed, which leads to a delay in restarting the operations. The problem has become greater recently because the volume of memory that an OS uses has increased and thus the time required to capture a dump tends to be longer.
Japanese Laid-open Patent Publication No. 10-333944 discloses a technology to solve the problem in which, by modifying an OS, a kernel of the OS is dumped and the OS is restarted beforehand and thus operations are restarted in parallel with capturing a dump of other parts. Further, Japanese Laid-open Patent Publication No. 2001-290677 discloses a technology in which a memory of a virtual machine in which a failure occurs is transferred to a standby virtual machine and the standby virtual machine is caused to dump the contents of the memory, which restarts operations more promptly.
In the technology disclosed in Japanese Laid-open Patent Publication No. H10-333944, it is assumed that the OS that is caused to operate on the virtual machine is deformed. Therefore, the technology may not be applied to cases where a commercially available compiled OS is caused to operate on a virtual machine. In the technology disclosed in Japanese Laid-open Patent Publication No. 2001-290677, memory transfer between virtual machines is necessary, which leads to a delay in restarting operations.